But what happens when your credit cards are cancelled after you die? That's a Catch-22 right there.
It avoids folks signing up, canceling the card and then riding for free.
Second, I don't know what payment you're using, but seriously consider paypal if you're not already, because I'm pretty sure you can setup yearly recurring "subscriptions" on paypal and people are much more likely to keep their paypal funding sources up to date. So you're not going to have to nag them to update credit card info every couple years and they're less likely to have occasion to think "do I really want to pay for this", it'll just be pay automatically.
I'm using Stripe at the moment.